Electrogramas auriculares endocárdicos anormales en pacientes de la tercera edad con fibrilación auricular paroxística idiopática / Abnormal atrial endocardial electrograms in aging patients with idiopathic paroxysmal atrial fibrillation

Los pacientes de la tercera edad están particularmente predispuestos a desarrollar episodios de fibrilación auricular paroxística (FAP), pudiendo ser los cambios que experimenta el miocardio auricular un factor contribuyente a la aparición de este fenómeno con el correr de los años. Por ende, diseñamos este trabajo con la idea de investigar los cambios que se producen en los electrogramas auriculares endocárdicos registrados por medio de un mapeo intraauricular con catéter en pacientes con FAP idiopática en la tercera edad. Realizamos un mapeo endocárdico con catéter de la aurícula derecha en ritmo sinusal en 72 pacientes con FAP idiopática para evaluar la influencia de la edad avanzada en los electrogramas auriculares endocárdicos. Los electrogramas bipolares fueron registrados de 12 sitios de la aurícula derecha, y un electrograma endocárdico auricular anormal fue definido como aquel que posee una duración ≥100 ms, y/o 8 o más deflexiones fragmentadas. Se registraron 864 electrogramas auriculares endocárdicos que fueron analizados cuantitativamente. El número de electrogramas auriculares anormales, así como la máxima duración y el mayor número de deflexiones fragmentadas de los electrogramas auriculares endocárdicos en los pacientes con FAP idiopática tuvo una correlación significativamente positiva con la edad. Se observó que la edad avanzada altera las propiedades electrofisiológicas del miocardio auricular haciéndolo más susceptible a desarrollar episodios de FAP. Estos cambios electrofisiológicos son más extensos conforme aumenta la edad. Existe un aumento progresivo en la extensión de la anormalidad electrofisiológica del miocardio auricular en pacientes de la tercera edad con fibrilación auricular paroxística idiopática.

There is a predisposition to develop paroxysmal atrial fibrillation (PAF) in aging patients,and theatrial musclechangesdue to the aging process could be a contributing factortothedevelopment of this tachyarrhythmia.Thus, we designedthis study to investigate thechangesobserved in the recorded atrial endocardial electrograms by means of an intra-atrial catheter mapping inpatients withidiopathicPAF. We performed an endocardialmapping of the right atrium in 72patientswith idiopathic PAFduring sinus rhythm toevaluate the influence of advancing age on the atrial endocardial electrograms. The bipolarelectrograms were recorded at 12 sites of the right atrium and an abnormal atrialelectrogram was defined as having a duration≥100 ms, and/or eight or more fragmenteddeflections.We recorded 864 atrial endocardial electrograms that were quantitativelyanalyzed. The number of abnormalatrial electrograms, as well asthe wider duration andthe greater number of fragmented deflections of the atrial endocardial electrograms,showed a significantpositive correlation with agingin patients with idiopathic PAF.It wasobserved that aging alters the electrophysiological properties of the atrial muscleincreasing the susceptibility to develop episodes of PAF. These electrophysiologicalchanges aremore extensivein advancing age. There is a progressive increase in theextension of the electrophysiologically altered atrial muscle in aging patients withidiopathicPAF.

Surfer's myelopathy: a radiologic study of 23 cases.

BACKGROUND AND PURPOSE: Surfing is an uncommon cause of an acute nontraumatic myelopathy. This study describes the MR imaging characteristics and clinical correlates in 23 subjects with surfer's myelopathy. MATERIALS AND METHODS: This was a retrospective review of 23 cases of surfer's myelopathy from 2003-2012. Spinal cord MR imaging characteristics and neurologic examinations with the use of the American Spinal Injury Association scale were reviewed. Logistic regression was used to determine associations between MR imaging characteristics, American Spinal Injury Association scale, and clinical improvement. RESULTS: All subjects (19 male, 4 female; mean age, 26.3 ± 7.4 years) demonstrated "pencil-like," central T2-hyperintense signal abnormalities in the spinal cord extending from the midthoracic region to the conus with associated cord expansion and varying degrees of conus enlargement on spinal cord MR imaging within 24 hours of symptom onset. T1 signal was normal. Faint gadolinium enhancement was present in a minority. Although there was a strong correlation between initial American Spinal Injury Association score and clinical improvement (P = .0032), MR imaging characteristics were not associated with American Spinal Injury Association score or clinical improvement. CONCLUSIONS: Surfer's myelopathy should be considered in the radiographic differential diagnosis of a longitudinally extensive T2-hyperintense spinal cord lesion. MR imaging characteristics do not appear to be associated with severity on examination or clinical improvement.

Improving hand hygiene adherence in an endoscopy unit.

BACKGROUND AND STUDY AIMS: Although hand hygiene is the most important measure in preventing infection transmission in healthcare settings, adherence to recommendations among healthcare workers is low. We implemented and assessed the impact of a World Health Organization-recommended educational intervention to improve hand hygiene adherence at the endoscopy unit of a Brazilian tertiary hospital. PATIENTS AND METHODS: Hand hygiene adherence and techniques used by healthcare workers of the endoscopy unit in the course of their duties were observed unobtrusively by four nurses from the infection control unit. Data were collected at every opportunity for hand hygiene. Evaluations were carried out before and 1 and 10 months after an educational intervention. The intervention consisted of task-orientated training sessions, with live demonstrations of the multitude of opportunities for hand hygiene and the appropriate techniques. In addition to assessing hand hygiene practices, we also evaluated staff knowledge through standardized questionnaires administered before and after the education intervention. Adherence was defined as hand hygiene/disinfection at an opportunity for hand hygiene. RESULTS: Adherence improved from 21.4 % before the intervention to 63.3 % 1 month and 73.5 % 10 months after the educational intervention. Correct answers to the questionnaire were 82.1 % on pre-intervention test and 85.7 % on post-intervention test. CONCLUSION: Hand hygiene rates were low before the education intervention and improved significantly after it. Against expectations, adherence to hand hygiene practices had increased further at 10 months after the intervention, reinforcing the intervention's positive impact.

Inactivation of Cryptosporidium parvum by ultrasonic irradiation.

The inactivation of Cryptosporidium parvum was investigated by the use of three different sonicators utilizing the squeeze-film effect, which may occur when ultrasound is irradiated into an extremely thin space and generate intensified pressure in the sample suspension. To expand from the small-scale horn-type sonicator to large-scale cylindrical or cleaning bath sonicators, the inactivation effectwas improved. In the case of the cylindrical sonicator (26.6 kHz, 30 W), 97% of the initial concentration of 2260 oocysts mL(-1) was inactivated at33 mL min(-1) (residence time of approximately 5.2 min). Hundreds of cubic meters of water can be treated per day at several kW using this sonicator. In addition, the simultaneous use of sonication and chlorination showed a beneficial effect on inactivation for C. parvum based on the evaluation of infectivity testing and morphological observation.

Endoscopic suprapapillary blunt dissection of the distal common bile duct in cases of difficult cannulation: a pilot series.

BACKGROUND AND STUDY AIMS: There is no consensus about the optimal alternative procedure in cases of failed cannulation of the common bile duct (CBD). The alternatives are usually considered to be high-risk procedures. This study describes endoscopic dissection of the distal biliary tract (EDBT) as a new technique in cases of difficult cannulation of the CBD. PATIENTS AND METHODS: Out of a total of 1057 patients in whom cannulation was attempted, deep cannulation failed in 49 patients, and 48 of those underwent EDBT. The procedure consists of cutting the mucosa, and the partial isolation of the distal part of the biliary tract using catheters, a needle-knife papillotome, and thin forceps. Access to the biliary tract was achieved with an endoscopic needle or forceps with or without electrocoagulation. RESULTS: EDBT was successful in all cases. In 46 patients EDBT was followed by standard sphincterotomy. Four patients developed clinical pancreatitis and hyperamylasemia occurred in 11 cases. Perforation, uncontrolled bleeding, and other complications did not occur in this series. CONCLUSIONS: EDBT is feasible, safe and constitutes a potential alternative for cannulation of the CBD. The endoscopic visualization of the wall structure and duodenal layers during the maneuvers at the papilla probably accounts for the absence of major complications.

Inactivation of Saccharomyces cerevisiae by ultrasonic irradiation.

We have investigated the inactivation of Saccharomyces cerevisiae (yeast cells) by ultrasonic irradiation. The amplitude on the vibration face contacting the sample solution was used as an indication of the ultrasonic power intensity. The effects of the amplitude on the vibration face and the initial cell numbers on the sonolytic inactivation of yeast cells have been investigated using a horn-type sonicator (27.5 kHz). The inactivation of the yeast cells by ultrasonic irradiation shows pseudo first-order behavior. The inactivation rate constant varied from 0.0007 to 0.145 s(-1) when the amplitude on the vibration face was in the range of 1-7 microm(p-p). The change in the inactivation rate constant as a function of the amplitude on the vibration face was similar to that of the OH radical formation rate under the same conditions. The threshold of this sonicator was 3 microm(p-p) with the amplitude on the vibration face. The initial cell numbers (from 10(2) to 10(5) mL(-1)) had an influence on the inactivation of the yeast cells by ultrasonic irradiation. The inactivation rate constants varied from 0.023 to 6.4 x 10(-3) s(-1), and the inactivation by ultrasonic irradiation was fastest at the lowest initial cell numbers. In a squeeze-film-type sonicator (26.6 kHz), 90% inactivation of the yeast cells was achieved by ultrasonic irradiation for 60 min.

Histologic analysis of the tibial bone tunnel after anterior cruciate ligament reconstruction using solvent-dried and gamma-irradiated fascia lata allograft.

Anterior cruciate ligament (ACL) reconstruction using free tendon graft requires biologic fixation in the bone tunnel. This report describes the intratunnel histology retrieved from a 47-year-old woman who underwent high tibial osteotomy 17 months after ACL reconstruction using a hybrid graft (a solvent-dried and gamma-irradiated fascia lata allograft as a core wrapped with iliotibial autograft). The patient underwent revision because of pain resulting from osteoarthrotic change, and the graft appeared to be taut and healthy on second-look arthroscopy. The sample was taken from the site of the metaphyseal osteotomy site. Histologic examination of the samples was performed with a light microscope (H&E and Masson trichrome stain). Biologic fixation of the graft to the bone was evident from observation of collagen fiber continuities, resembling Sharpey fibers. Integration of the autograft and allograft seemed to have occurred; the junction between the allograft and the autograft could not be determined. However, there was a difference in ligamentization depending on location. In the peripheral region of the graft (the autograft region), the collagen fibers showed a distinct crimped pattern; the fibroblasts were arranged regularly along the major axis of the collagen fiber bundle. In the central part of the graft (the allograft region), remodeling seemed to be delayed. There were acellular, bubbly or myxoid degeneration areas in which the fiber bundles were less oriented and there was increased vascularity.

Experimental endoscopic repair of gastric perforations with an omental patch and clips.

BACKGROUND: The omental patch is a standard surgical treatment of gastroduodenal ulcer perforation. This is a report of an experimental method for endoscopic repair of anterior gastric perforations with an omental patch developed by using a porcine model. METHODS: A standardized gastric perforation was created in 10 pigs. The omentum was pulled into the gastric lumen and fixed endoscopically to the muscularis propria layer of the stomach with metallic clips. RESULTS: The postoperative course was normal in 9 animals. An ulcer was evident at the site of repair at follow-up endoscopy. At autopsy, the omentum was adherent to the external side of gastric wall. One animal died with peritonitis, presumably because the muscularis propria layer could not be seen during the procedure, and the clips attached the omentum only to the mucosa. CONCLUSIONS: Endoscopic repair with an omental patch appears to be an effective procedure for closure of gastric perforations.

Endoscopic treatment of Zenker's diverticulum.

BACKGROUND: The most important aspect of the surgical management of Zenker's diverticulum is probably the cricopharyngeal myotomy. Endoscopic diverticulotomy can be performed with a needle-knife papillotome, which allows simultaneous myotomy of the upper esophageal sphincter. METHODS: Since 1978, 47 patients (28 men and 19 women 51 to 81 years of age) underwent endoscopic diverticulotomy. Most patients underwent more than one treatment session (mean value 2.2). The procedure was performed with sedation. Tubes were not used, and oral intake of food was begun the first day after the operation. RESULTS: Forty-five (95.74%) patients had no dysphagia or only occasional, mild dysphagia during the postoperative course. No fistula, no recurrent laryngeal paralysis, and no deaths occurred. CONCLUSION: Endoscopic diverticulotomy seems to be a good choice of therapy at least for patients with associated diseases that increase surgical risk.

Results of the routine use of a modified endoprosthesis to drain the common bile duct after laparoscopic choledochotomy.

BACKGROUND: One hundred eighty-one patients were submitted to laparoscopic common bile duct exploration. METHODS: A transcystic approach was used in 147 patients, choledochotomy in 14, and both in 20. The indications to perform a choledochotomy included stones larger than 20 mm, stones proximal to the cystic duct entrance, and cases in which the transcystic duct approach proved impossible or unsuccessful. RESULTS: The common bile duct was drained by a T-tube in four patients, by laparoscopic sphincterotomy in one, by laparoscopic choledochoduodenostomy in one, and by a 10 Fr endoprosthesis in 28. The stent placement was technically feasible in all patients but one. The biliary drainage was adequate. Mean hospital stay was 2.1 days. Complication was limited to one umbilical infection and one self-limited biliary leak. CONCLUSIONS: The procedure proved to be technically simple, safe, and efficient, and resulted in a low morbidity rate and short hospital stay.

[Synthesis and antiulcer activity of N-2-(2-hydroxy-2-phenyl)ethyl-N"-(methanesulfonyl)guanidine analogue of ranitidine. Development of a new antiulcer agent T-593].

A series of the aryl-substituted N'-2-(2-hydroxy-2-phenyl)ethyl derivatives of N"-methanesulfonyl-N-2-((5-dimethylaminomethyl or 5-methylaminomethyl) furfurylthio)ethylguanidine have been synthesized as potential antisecretory and mucosal protective antiulcer agents. The synthetic routes involves, at the last stage, the reaction of 2-hydroxy-2-phenylethylamines with N-2-(furfurylthio)-ethyl-N'-methanesulfonyl-S-methylisothiourea or its O-phenylisourea counterpart. The primary screening test to assess the inhibitory activity of the synthetic compounds on histamine-induced gastric acid secretion was carried out in anesthetized rats by the lumen-perfusion technique of Ghosh and Schild and also by the pylorus-ligated preparation method. The best profile of histamine H2-antagonist activity was much better than that of the prototype ranitidine, and obtained with N'-(2-(2-hydroxy-2-(4-hydroxyphenyl)) ethyl-N"-methanesulfonyl-N-2-(5-(methylaminomethyl)furfurylthio)et hylguanidine (12f), which was also characterized by enhancing the gastric mucosal blood flow in rabbits as observed by the thermoelectric method. This compound 12f, designated as T-593, significantly inhibited the formation of the indomethacin-induced gastric lesions in rats; 3.5-fold more potent than ranitidine, but 4-fold less active than famotidine. On the other hand, T-593 and famotidine displayed comparable activities in healing the acetic acid-induced gastric ulcer with and without the dosing of indomethacin. Additional notable features of T-593, as determined in rats, are that its protective effect on the hemorrhagic shock-induced lesion under the prior dosing of histamine is ca. 10- and 2-fold greater than ranitidine and famotidine, respectively, and that a decrease in the gastric mucosal blood flow caused by a partial blood-withdrawal is more strongly recovered with T-593 than with famotidine. These experimental results suggest that the antiulcer efficacy of T-593 can be explained by its dual activities: antisecretion of gastric acid and, more importantly, protection of gastric mucous membrane.

[Influence of T-593 on the recurrence and relapse of cryocautery-induced gastric ulcer in rats: sequential observation with an endoscope and histological evaluation].

We investigated the influence of T-593, a novel anti-ulcer agent, on the recurrence and relapse of cryocautery-induced gastric ulcer in rats, in comparison with the action of famotidine and ranitidine. The drugs were administered from the 7th to the 119th day and then discontinued to the 190th day after induction of gastric ulcer. The healing, recurrence and relapse process of gastric ulcer was sequentially observed with an endoscope. In the control group, the reduction of ulcer index was observed until the 76th day after ulcer induction followed by aggravation, suggesting the recurrence and relapse occurred on cryocautery-induced gastric ulcer in rats. In the famotidine and ranitidine groups, the recurrence and relapse occurred after cessation of administration. The recurrence and/or relapse rate of T-593 was lower than those of other drugs. In the histological measurement, the grades of heterotopic regenerated gland and inflammatory cell infiltration of T-593 was lower than those of the control and other drugs in the ulcer area. From these results, it is concluded that T-593 induces ulcer healing with a lower recurrence and/or relapse rate of ulcers than other conventional H2-antagonists, and T-593 may thus be a useful anti-ulcer drug for clinical therapy.

Analysis of primate major histocompatibility complex (MHC)-DQA1 locus by PCR-single strand conformation polymorphism (SSCP).

Major histocompatibility complex (Mhc) gene products play an important role in the immune responses against pathogens and autoimmunity, disease resistance and transplantation. Non-human primates (NHPs) are increasingly being utilized as models to test the safety and efficacy of candidate vaccines. Mhc typing of NHPs is an important component of the vaccine trial studies and in the investigations of any associations between Mhc alleles and disease. Routine typing of primate Mhc alleles has been hampered by unavailability of well characterised immunological reagents. In this study, we have used PCR amplification and SSCP for screening polymorphisms in the primate DQA1 locus. Using this technique, 9 African primate species (36 individuals) were analyzed. Ten individuals showed three or four electrophoretic band patterns and the rest two-band patterns indicating this technique can be used to discriminate homozygous and heterozygous individuals prior to DNA sequencing. This method may also be used to screen primates for Mhc-DQA1 allelic polymorphism. However, practical application of this technique for routine typing of primate Mhc-DQA1 alleles depends on availability of adequate nucleotide sequence information.

Laparoscopic Antegrade Sphincterotomy.

The authors describe the technique and results of laparoscopic antegrade sphincterotomy. The procedure was performed in 42 selected cases of choledocholithiasis. The indications for attempting laparoscopic antegrade sphincterotomy included impacted stones in the papilla, multiple common bile duct stones, one or more common hepatic or intrahepatic stones, dilated common bile duct requiring a drainage procedure, suspicion of papillary stenosis, whenever numerous fragments are found after lithotripsy, and as an adjunct procedure when the surgeon cannot completely remove all the stones in the bile ducts. No major complications or mortality was observed. One patient had a self-limited drop in the hematocrit and four patients presented with transitory mild hyperamylasemia that returned to normal levels in 72 hours. Laparoscopic antegrade sphincterotomy added an average of 17 minutes to the laparoscopic operation. The mean postoperative stay was 1.4 days. The results of this study conclude that laparoscopic antegrade sphincterotomy is an option of great therapeutic value for selected cases when drainage of the biliary tract concomitant to the treatment of choledocholithiasis is necessary.

Laparoscopic reoperations after failed and complicated antireflux operations.

Nineteen patients underwent laparoscopic reoperations for failed or complicated antireflux operations from a total of 248 patients with gastroesophageal reflux disease who had been operated on by this approach. Sixteen had been submitted to open surgery and three to laparoscopic surgery over a period ranging from 5 days to 31 years before the study. Three patients had been submitted to two open antireflux surgeries previously. Seventeen patients had recurrent reflux esophagitis after different types of surgeries, and two patients presented with gastric strangulation after fundoplication. The causes of recurrence were: slipped total fundoplications (3), disruption of total and partial fundoplications (6), too-tight total fundoplication (1), too-low (gastric) partial fundoplication (1), Allison procedure (1), partial fundoplication and paraesophageal hernia (2), and unknown (3). The laparoscopic approach was used in 18 patients and a laparoscopic-thoracoscopic approach in 1. The procedures included laparoscopic total fundoplications (11), partial fundoplications (4), transhiatal esophagectomy (1), Collis-Nissen (1), Roux-en-Y gastrectomy and thoracoscopic vagotomy (1), and intrathoracic fundoplication (1). One patient was converted to open surgery. Intraoperative complications included 1 pneumothorax, 1 gastric perforation, and 1 esophageal perforation during the introduction of a Maloney dilator. Mean operative time was 210 min, ranging from 140 to 320 min. Mean hospital stay was 3.1 days after treatment of failed operations and 22 days after treatment of complications. Postoperative complications included subcutaneous infection (1), gastric fistula (1), and liver hematoma (1). The results have been excellent and good in 84.3% of the patients after a mean follow-up of 13 months. We concluded that laparoscopic reoperations are technically feasible with good preliminary results provided that the mandatory expertise is available.